Code sorter printer tube



Sept. 5, 1961 c. H. CASH EI'AL CODE SORTER PRINTER TUBE 5 Sheets-Sheet 1 Filed Aug. 8, 1955 IN V EN TORS S 5 wk. m m H Em NR N Sept. 5, 1961 c. H. CASH ETAL 2,999,178

coma: SORTER PRINTER TUBE Filed Aug. 8, 1955 3 Sheets-Sheet 2 4n gg, 2p ll lj q 24 3| 4| 5| 4| 7| 2 I2 22 32 42 52 e2 22 313 23 55 43 52. 43 23 Fig. 3

INVENTOR. CARLTON H. CASH WILL/S R. UAW/R5 A TTORNEYS Sept. 5, 1961 Filed Aug. 8, 1955 C. H. CASH El'AL CODE SORTER PRINTER TUBE 3 Sheets-Sheet 3 INVENTOR.$ CARLTON H. 0451-! WILLIS a 0A WIRS ATTORNEYS United States Patent Calif.

Filed Aug. 8, 1955, Ser. No. 527,182

Claims. (Cl. 3'1'3- 7 7) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to code sorting and printing tubes and more particularly to tubes which form a visible character for each On-Ofl combination (code) of a plurality of individual voltages.

Heretofore numerous devices have been used in which an electron beam of a cathode ray device is moved about the face of the tube by means of a deflection system, for example, as on a TV screen or oscilloscope. Other devices pass the electron beam through a matrix of letters,

slots, or symbols cut in stencil fashion and located be tween the gun and fluorescent tube face by applying appropriate voltages to deflection plates. However, in these cases the amount of deflection of the beam is dependent upon the amount of voltage applied to the deflection plates from a plurality of sources. This makes the amplitude of the applied voltage a critical factor and a source of error in determining which combination of voltage sources are being simultaneously applied. in the code sorter tube invented by Keeran, Patent No. 2,925,507, each set of deflection plates had a separate effective point of deflection spaced at different points along the axis of the tube. This produced a small deflection error which was permissible in a code Sorter tube in which the pin contacts did not have to be struck dead center by the electron beam, the contact being sufli'ciently effective by striking any portion of the pin.

The code sorter printer tube of the present invention comprises a cathode-ray electron tube consis'ting'of an electron gun, a special deflection system, a letter forming device and a phosphor screen, all enclosed in a vacuum tight envelope With appropriate through-glass leads and bases. This tube sorts and decodes any combination of incoming individual voltages independently of their amplitude and duration by connecting the various voltage sources to sets of deflection plates which are so shaped, positioned, and arranged that they deflect each single unit of voltage by varying units 'of deflection of the beam. The beam passes through a matrix having character forming slots which form letters or numbers on a phosphor coated screen for visual observation.

The novel deflection system makes the effective point of deflection the same for all sets of deflecting plates and combinations of signal voltages so that no matter where the matrix is positioned betweenthe deflection plates and face of the tube there is no beam deflection error in striking the numbers and the numbers are always evenly spaced and printed on the face of the tube. This could not be achieved, for example, by the deflection system in the Keeran tube since any fractional error in beam deflection would cause uneven spacing or overlapping of the numbers. By using a Monel barrier gridclosely spaced from the tube face, post acceleration, necessary to obtain proper number brightness and clarity with the required low duty cycle, is achieved without affecting the deflection sensitivity of the deflection system. Within the deflection system provision is also made to overcome barrel distortion by introduction of opposite or pincushion distortion so that the numbers appear in straight columns and rows instead of being slightly curved.

similar sources.

2 The advantages of this invention are that all decoding and sorting is accomplished in a single tube in a straight;

forward manner with a minimum of components and with maximum reliability. The tubecan accept pulses 0:1 microsecond-ajaartand yet the beam strikes the phosphor sufficiently fast to obtain a visual readout. Extreme ac curacy is achieved in beam deflection and barrel dis tortion is overcome. Tube age has no effect on sorting, only the output decreases. The tube operates accurately until the reduced output of the gun reduces the target output voltage to an unusable value.

It is therefore an object of this invention to provide an improved code sorting and printing tube.

Another object is the provision of an improved code sorter and printer tube having a plurality of deflection plates which deflect each unit of voltage by predetermined varying amounts without varying the deflection plate voltage amplitude.

Another object is the provision of a novel multi-elec trode electron beam deflection system in which the eifec= tive point of deflection is the same for all combinations of input voltages.

Another object is the provision of a code sorter and printer tube in which the beam character shaping function may be positioned at any point between the deflection plates and face of the tube without causing char-ac ter blur or irregular alignment of the characters on the face of the tube. 7

Still another object is the provision of a beam deflection system which overcomes barrel distortion through in troduction of opposite or pincushion distortion.

A still further object is the provision of post acceleration which will increase the speed of the electron beam to strike the phosphor screen at the required high speed fora low duty cycle withoutaffecting the deflection sensitivity of the deflection system.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connectionwith the accompanying drawings wherein:

FIG. 1 is a perspective view of the tube with. broken away to show the interior thereof;

FIG. 2 is a perspective view of a modification in which the matrix is positioned rearwardly from the face of the tube; 7

FIG. 3 is a front view of'the printed numbers on the tube face after compensation is made for barrel distortion; and

parts FIG. 4- and FIG. 5 Show the relative widths, spacing input is six individual voltages of equal amplitude, any

one or combination of which may be On or Oil. The input voltages may be derived from ll-C. power supplies, coincidized pulse trains, detected tones, detected RF and These voltages drive electron beam as: flection plates and therefore require very little power-z Since these tubes accept six input voltages and select a separate output position for any'cornbination of input voltages, these tubes can be used for communication, tclemetering remote control, indicators, computers; etc. By using two tubes a 7-digit input code with 128 outputs can be obtained.

Referring now to the drawings in which like numerals I refer to like parts throughout the several views, there is shown in FIG. 1 a perspective view of the tube. The vacuum tight envelope 11 has a base end sealed and tipped ofi with a standard lead stem. The electron gun base 12 is a standard small-shell duodecal. Spaced from base 12 is a second lead seal for the deflection system base 13, a medium-shell-diheptal with the center removed so as to pass over the smaller diameter of the tube. Both seals may be formed in any conventional manner suitable for bringing leads out from elements within a vacuum tube. The electron gun 14 is of the standard electrostatic focus type. The deflection system comprises sets of plates connected to six individual voltage sources so as to deflect the electron beam by varying amounts. Plates 15, 16, 17 deflect the beam horizontally 1, 2, and 4 units respectively and plates 18, 19, 20 deflect the beam vertically 1, 2, and 4 units respectively.

As shown in FIG. 4 and FIG. 5, these plates comprise a plurality of pairs of strips. 15A and 15B are connected to one lead and when energized deflect the beam horizontally one unit. 16A, 16B and 160 are connected to another source and combine to deflect the beam two units horizontally. 17A, 17B, and 17C are connected to a third source and deflect the beam four units horizontally when energized. With the beam originally positioned in a neutral position, for example, to strike in FIG. 3, combinations of voltages on plates 15, 16, and 17 will deflect horizontally up to eight units. Similarly, plates 18, 19, and 20 are capable of deflecting progressively up to eight units vertically. 18A and 18B connected to one source deflect one unit, 19A, 19B, and 19C connected to a second source deflect the beam two units, and 20A, 26B, and 20C deflect four units. In the six unit code, exemplifying this invention, there are 64 individual combinations. The individual voltages are connected to the individual plates: voltage A to plates 18, voltage B to 19, and voltage C to plates 20, voltage D is connected to plates 15, voltage E is connected to plates 17, and voltage F to plates 17. The beam is initially positioned on the 0 of the beam shaping mask.

The portion of the beam passing through the mask, strikes the phosphor screen in the shape of the engraved character causing an illuminated character to show on the tube face. When code 0 is applied to the deflection plates, no additional voltage is applied so the beam stays at O and a 0 is printed on the face of the tube. Code 1 applies voltage A to deflection plates 18 which moves the beam one unit down to the mask number 1 thus printing the number 1 on the tube face. Code 2 applies voltage to plate 19 which moves the beam two units down to the number 2, printing a number 2. Code 3 applies voltage to plates 18 and plates 19 giving deflections of one and two units which add vectorially to give three units of deflection to the number 3. Code 4 gives four units of deflection on plates 20 to print number 4. Similarly, code applies a unit of voltage to plates giving one unit vector at 90 (horizontally) to number 10 to print 10 on the tube face. Carrying the system further, all combinations of the six vectors produce deflections which select the individual numbers in the mask corresponding to the individual codes. The electron gun may be gated to print only at the time of deflection. A plurality of tubes may be used in which case further tubes provide additional numbers or act as multipliers for the first.

A plurality of pairs of strips spaced axially along the path of the beam are provided instead of single pairs of plates connected to each signal source. This is to provide for a single effective point of deflection for all pairs of deflection plates, a condition necessary for an accurate deflection system with a character forming matrix positioned at any point between the system and the printing surface of the tube. Otherwise, character blur and irregular alignment of characters on the tube face will occur.

The eifective point of deflection is defined as the point between a pair of deflection plates at which the path of the electron beam entering the defl ction region intersects 4 I 1 the path of the electron beam leaving the deflection region. In providing a single effective point of deflection and also maintaining the proper amount of deflection, the spacing and relative widths of deflecting strips are critical. So also is the distance between strips of the same pair. The pair closest to the electron gun are D distance apart and the pair at the other end 2.8D apart. By inter leav-ing and extending the plates beyond the square box configuration, adjacent sets of plates will not disturb the electric field of adjacent sets of plates. This prevents distortion found in box-like types of deflection plates. The length and width and spacing along the tube determine amount of deflection and the position of effective point of deflection of beam. It may be observed in FIG. 1 that the various plates or strips are in a sense interleaved, that is for example, the electrode 17A is interleaved between the electrodes 21A and 19A; whereas the set of electrodes 19A is interleaved between the sets'of electrodes 17A and 16A, etc. For want of better terminology, the sets of plates may be said to be arranged in an interleaved criss-cross fashion along the electron beam path.

Upon inspection of the vertical and horizontal strips in FIG. 4 and FIG. 5, it is noted that corresponding horizontal and vertical strips are identical except that strip 20A is 2L wide and 17A is 2.4L wide. This is because strip 20A is closer to electron gun 14 and requires less width for the same amount of deflection. It does not matter whether strips 20A and 17A are horizontally or vertically deflect-ing insofar as their respective widths are concerned. It is important only that the more narrow of the two strips be closer to the electron gun.

While the deflection system of the present invention just described has less barrel distortion than others, some distortion still exists. Barrel distortion causes a slight rounding of the rows and columns of characters instead of the desired straight alignment. The remaining slight barrel distortion is corrected by the introduction of opposite or pincushion distortion. This is done by incorporating equalizer pins 21 in the corners at the end of the deflection system. By changing the potential on these pins, the pattern can be made to go from barrel distortion to straight alignment to the other extreme of pointed corners.

In situations where very low duty cycles are desired, in order to eflect a visual presentation on the phosphor screen at the face of the tube, the sensitivity of the phosphor, the beam current and acceleration of the beam must be considered. The phosphor having the best efliciency in light output per watt of power input and also having a light output frequency corresponding to the most sensitive range of the human eye is desirable. As current density increases the phosphor efliciency decreases but when the speed of the electrons increases the phosphor efi'iciency also increases. Therefore, the light output of the phosphor can be increased better by increasing the acceleration of the electrons from gun 14. However, increased acceleration through the deflection system makes it less sensitive so it is desirable to permit normal electron acceleration through the deflection system and increased acceleration thereafter. This is done by post acceleration.

Since the conventional method of applying accelerating potentials on Aquadag rings between the deflection system and the tube face caused some deflection of the beam, a new method was devised. As shown in FIG. 1 a Monel barrier grid 22 is mounted in close proximity to the tube face. The inner face of the tube is aluminized at 2 6 with the characters engraved therethrough. A phosphor coating 27 is then applied and backed by another aluminized coating 28. A high voltage is then placed on the aluminized and engraved tube face. The electrons upon passing through the Monel barrier grid are thus accelerated and strike the phosphor screen at the desired high speed. The Monel barrier grid 22 completely shields the portion accents the Monel screen and tube face are essentially arallel conductors, the electrons passing through the Monel screen are accelerated in a direction perpendicular to these planes. Therefore, the deflection sensitivity is completely independent of this acceleration voltage.

Since coating and engraving the inner tube face presents certain production problems, it may be desirable to use a matrix mask 23 positioned between the deflection system and the tube face as shown in FIG. 2. With the matrix mask positioned between'the deflection system and Aquadag rings, the use of Aquada'g rings 24 is satisfactory for post acceleration. However, greater sensitivity is achieved by replacing the Monel screen 22 with the matrix 23 (in which case it also acts as the barrier grid). In this modification, an aluminized coating 28 over the phosphor screen is used. A high voltage on the aluminized screen then provides the necessary post acceleration. This type of character forming requires stencil type characters whereas the engraved aluminized tube face does not. However, it has the advantage of increased electron current though the cut-out symbol. between the tube face and the mask gives a lense action at the symbol and secondary emitted electrons from the mask will be sucked through the symbol slot. Also primary electrons that are slightly off the number slot will be pulled through due to focusing action.

The mask 23 is preferably made of a low secondary emission material such as carbon. However, since carbon is diflicult to fabricate into a character forming mask, a brass or copper sheet with a thin layer of carbon deposit proved satisfactory.

Other modifications from time to time will occur to those skilled in the art. For example, the stencil mask might be removed and phosphor letters painted on the face of the tube where the individually deflected beam impinges for each code. Also the total number of possible code combinations may be increased or reduced, the total number possible is 2 where n is the number of individual On-Ofl' voltages. These and other modifications may become obvious in the light of the above teachings and may be resorted to without departing from the spirit and scope of the invention, as hereinafter defined by the appended claims, as only two preferred embodiments thereof have been disclosed.

What is claimed is:

1. A code sorting and printing tube comprising a vacuum sealed envelope, electron beam receiving means at one end thereof, electron beam projecting means opposite said receiving means, a plurality of sets of horizontal deflection means having external electrical connections thereto, each of said sets of horizontal deflection means axially disposed between said beam projecting means and said receiving means for deflecting said beam in a horizontal direction, a plurality of sets of vertical deflection means having external electrical connections thereto, each of said sets of vertical deflection means axially disposed between said beam source and said receiving means for deflecting said beam in a vertical direction, said plurality of sets of horizontal deflection means and said plurality of sets of said vertical deflection means alternately disposed between said beam source and said receiving means, each of said sets having predetermined dimensions so that said beam is deflected a predetermined increment when a predetermined amplitude of control signal voltage is applied to said external connections and character forming means disposed between said horizontal and vertical deflection means and said receiving means, said character forming means having different characters each of said characters corresponding and responsive to a different combination of said horizontal and vertical deflection increments.

2. The code sorting and printing tube of claim 1 wherein each of said sets of horizontal deflection means comprises a plurality of pairs of deflection plates, and each of Said sets of vertical deflection means comprises a plurality The intense electric field of pairs of deflection plates, a first one at s d sets of horizontal deflecting means having dimensions such that said beam is deflected one unit with a voltage. E .applied to said external connections, a second one of saidfsetfs "of horizontal deflection means having dimensions such, that said beam is deflected two units with said voltage E applied to said external connections, a third one of said horizontal deflection means having dimensions such that said beam is deflected four units with said voltage E applied to said connections, a first one of said sets ofvertical deflection means having dimensions such that'said beam is deflected one unit with a voltage E applied to said external connections, a second one of said sets of vertical deflection means having dimensions such that said beam is deflected two units with said voltage E applied to said external connections, a third one of said vertical deflection means having dimensions such that said beam is deflected four units with said voltage E applied to said external connections.

3. A code sorting and printing tube comprising a vacuum sealed envelope, electron beam receiving means at one end thereof, electron beam projecting means opposite said receiving means, eight pairs of horizontal deflection plates having external electrical connections thereto, each of said pairs of horizontal deflection plates axially disposed between said beam projecting means and said receiving means for deflecting said beam in a horizontal direction, eight pairs of vertical deflection plates having external electrical connections thereto, each of said pairs of horizontal deflection plates axially disposed between said beam projecting means and said receiving means for defleeting said beam in a vertical direction, said eight pairs of horizontal deflection plates and saideight pairs of vertical deflection plates alternately disposed between said projecting means and said receiving means, each of said sets having predetermined dimensions such that said beam is deflected a predetermined increment when a predetermined amplitude of signal voltage is applied to said external connections, and character forming means disposed between said horizontal and vertical deflection means and said receiving means, said character forming means hav- 5. A code sorting and printing tube comprising a vacuum sealed envelope, electron beam receiving means at one end thereof, electron beam projecting means opposite said receiving means, a plurality of pairs of horizontal deflection means, each of said pairs of horizontal deflection means axially disposed between said beam projecting means and said receiving means for deflecting said beam in a horizontal direction, a plurality of pairs of vertical deflection means, each of said pairs horizontal deflection means axially disposed between said beam projecting means and said receiving means for deflecting said beam in a vertical direction, said plurality of pairs of horizontal deflection means alternately disposed between said beam source and said screen, each of said pairs having predetermined dimensions such that said beam is deflected a predetermined increment when a predetermined amplitude of signal voltage is applied thereto, character forming means disposed between said horizontal and vertical deflection means and said receiving means, said character forming means having different characters each corresponding to a different combination of said horizontal and vertical deflection increments.

over

References Cited in the file of this patent UNITED STATES PATENTS 8 McNaney...; Sept. 20.v 1955 Smith Dec. 27, 1955 MeNaney Dec. 27, 1955 McNaney Feb. 21,1956 i Bryant et a1 July 3, 1956 Tompkins Aug. 6', 1957 McNaney Aug. 20, 1957 Keeran Feb. 16, 1960 OTHER REFERENCES The Type C19K Charabteron Tube and Its Applica tions to Air Surveillance Systems, by J. T. McNaneyl, IRE Convention Record (1955), part 5, pp. 31-36. 

